Drying Effects
Air Check
- Occurs early in drying process if too much moisture is removed from the outer portion of the lumber before the inner portion has lost moisture and shrunk
- Shown in Red Oak with air check or surface check
Honey Comb
- Not natural, but common
- Occurs when kiln temperatures are raised before the lumber core moisture has been lowered sufficiently
- Example shows end grain and lumber ripped in half to expose the severe interior honeycomb
Shake
- Also called ring shake or wind shake
- Caused by bacteria weakening the area between growth rings
- Bacteria may have a vinegar or rancid smell prior to drying
- Shown in Red Oak
- Flatsawn portion shows typical shake
- End grain portion shows ring failure
Splitting or Cracking
- May occur in any wood type
- May be minimized by proper end coating of logs or lumber before drying
- Shown in Red Oak